docs: Split Mac install instructions

Okay, so I think this is what happened to me:
1) I had brew installed on my Intel Mac
2) I got an Apple Silicon Mac
3) I setup my new Mac by copying over Intel Mac harddrive
4) I now have two brew's installed on my machine:
  a) /usr/local/bin/brew (for intel macs & cross-compiling)
  b) /opt/homebrew/bin/brew (for (for apple silicon)
5) The wrong brew was in my path (a)
Looking through our getting started docs, we seem to reference both /usr/local/... and  opt/homebrew/...

Update the installation document to mac this and related issues more clear for new users who might run into this problem.

Changelog-None

Author: ddustin

doc/getting-started/getting-started/installation.md

@@ -324,30 +324,49 @@ poetry install
 make
 ```
 
-## To Build on macOS
+## To Build on macOS Apple Silicon
 
-Assuming you have Xcode and Homebrew installed. Install dependencies:
+Assuming you have Xcode and Homebrew installed.
 
+First confirm which architecture of Mac you are running
 ```shell
-brew install autoconf automake libtool python3 gnu-sed gettext libsodium protobuf lowdown
-export PATH="/usr/local/opt:$PATH"
+arch
 ```
+If you see this result: `arm64`
+Continue with these instructions. If you see any other result switch to Build on macOS Intel instructions.
 
-If you need SQLite (or get a SQLite mismatch build error):
-
+Confirm you are using Apple Silicon Homebrew
 ```shell
-brew install sqlite
-export LDFLAGS="-L/usr/local/opt/sqlite/lib"
-export CPPFLAGS="-I/usr/local/opt/sqlite/include"
+which brew
+which pkg-config
+```
+If you see this result:
 ```
+/opt/homebrew/bin/brew
+/opt/homebrew/bin/pkg-config
+```
+You are using Apple Silicon Homebrew and can continue with the instructions, skip to "Install dependencies"
+
+If you see this in the result: `/usr/local/bin/brew`
+You are using brew in Intel compatibility mode. The simplest solution is to remove brew entirely, reinstall it, and start these instructions over.
 
-Some library paths are different when using `homebrew` on Macs with Apple silicon, therefore the following two variables need to be set for Macs with Apple silicon:
+Install dependencies:
 
 ```shell
+brew install autoconf automake libtool python3 gnu-sed gettext libsodium protobuf lowdown pkgconf
+export PATH="/opt/homebrew/opt/:$PATH"
 export CPATH=/opt/homebrew/include
 export LIBRARY_PATH=/opt/homebrew/lib
 ```
 
+If you need SQLite (or get a SQLite mismatch build error):
+
+```shell
+brew install sqlite
+export LDFLAGS="-L/opt/homebrew/opt/sqlite/lib"
+export CPPFLAGS="-I/opt/homebrew/opt/sqlite/include"
+```
+
 Install uv for Python dependency management:
 
 ```shell
@@ -385,6 +404,11 @@ Build lightning:
 ```shell
 uv sync --all-extras --all-groups --frozen
 ./configure
+```
+
+If you see `/usr/local` in the log, an Intel compatability dependency has been picked up. The simplest solution is to remove brew entirely, reinstall it, and start these instructions over.
+
+```shell
 uv run make
 ```
 
@@ -406,10 +430,88 @@ To install the built binaries into your system, you'll need to run `make install
 make install
 ```
 
-On a Mac with Apple silicon, you may need to use this command instead:
+You may need to use this command instead. Confirm the exported PATH, CPATH, and LIBRARY_PATH environment varaibles set earlier are still present.
+```shell
+sudo make install
+```
+
+## To Build on macOS Intel
+
+Assuming you have Xcode and Homebrew installed.
+
+Install dependencies:
+
+```shell
+brew install autoconf automake libtool python3 gnu-sed gettext libsodium protobuf lowdown pkgconf
+export PATH="/usr/local/opt/:$PATH"
+export CPATH=/usr/local/include
+export LIBRARY_PATH=/usr/local/lib
+```
+
+If you need SQLite (or get a SQLite mismatch build error):
+
+```shell
+brew install sqlite
+export LDFLAGS="-L/usr/local/opt/sqlite/lib"
+export CPPFLAGS="-I/usr/local/opt/sqlite/include"
+```
+
+Install uv for Python dependency management:
+
+```shell
+curl -LsSf https://astral.sh/uv/install.sh | sh
+```
+
+After installing uv, restart your shell or run `source ~/.zshrc` to ensure `uv` is in your PATH.
+
+If you don't have bitcoind installed locally you'll need to install that as well:
+
+```shell
+brew install boost cmake pkg-config libevent
+git clone https://github.com/bitcoin/bitcoin
+cd bitcoin
+cmake -B build
+cmake --build build --target bitcoind bitcoin-cli
+cmake --install build --component bitcoind && cmake --install build --component bitcoin-cli
+```
+
+Clone lightning:
+
+```shell
+git clone https://github.com/ElementsProject/lightning.git
+cd lightning
+```
+
+Checkout a release tag:
+
+```shell
+git checkout v24.05
+```
+
+Build lightning:
 
 ```shell
-sudo PATH="/usr/local/opt:$PATH"  LIBRARY_PATH=/opt/homebrew/lib CPATH=/opt/homebrew/include make install
+uv sync --all-extras --all-groups --frozen
+./configure
+uv run make
+```
+
+Running lightning:
+
+> 📘
+>
+> Edit your `~/Library/Application\ Support/Bitcoin/bitcoin.conf`to include `rpcuser=<foo>` and `rpcpassword=<bar>` first, you may also need to include `testnet=1`.
+
+```shell
+bitcoind &
+./lightningd/lightningd &
+./cli/lightning-cli help
+```
+
+To install the built binaries into your system, you'll need to run `make install`:
+
+```shell
+make install
 ```
 
 ## To Build on Arch Linux